I remember reading somewhere that RB411’s mPCI slot is current limited <1A. Is that true? XR9 needs up to 1.2A so I want to make sure that RB411AH can deliver.
thanks!
The XR9 works fine with RB411 family and all other RouterBoards. We have sold many of the RB411 together with XR9 cards in assembled radios with no complaints.
According to the Mikrotik RB411 data sheet, the RB411 draws about 3 watts but can draw up to 12 watts with a mini-PCI card installed. That leaves 9 watts for the card. If you are powering the RouterBoard with 12vdc then your 1 amp maximum power draw would make sense. But that is 1 amp at 12vdc, not 3.3vdc which is what the XR9 is running at.
You really need to work in watts and not amps. The formula is P=IE or Power (in watts) = amps * volts. Since the RB411 has 9 watts available at 3.3vdc then the RB411 can source about 2.73 amps, not just 1 amp. If we convert the XR9 maximum current consumption of 1.1 amps at 3.3vdc to watts, we only need a maximum 3.63 watts for the XR9.
You have plenty of power to spare.
Tom
Thanks. Anyone else running recent 411 with XR9?
I’m running XR9s in both an RB411 and RB411U. I have 200’ runs of CAT5 and get constant reboots whenever I increase the transmitter power over 1 db. It works fine with 1 dbm and on short runs of CAT5, when the antennas are just a few feet apart (about 35 mbps average), but gets wildly unstable otherwise. I had to drop the power to nearly nothing before it would even work in that configuration, but I was under the assumption that the higher power was just overloading the receivers at such close range.
BTW, it stays connected just great until I run the bandwidth test <where usually there’s a ‘splat’ before a reboot>.
But just for giggles, I’m gonna swap out the XR9s for some SR71s just to see what happens. Then I guess its drop the multimeter across the terminals and hit the speed test again.
Oh, I’m using Ubiquiti 24v POE adapters.
If anyone has seen this issue before and has some insight. Everything seems within spec.
tnx
-r